What mass of water will react with sodium if 12 g of hydrogen is formed as a result of the reaction?

Reaction equation: 2Na + 2H2O = 2NaOH + H2.
1) Find the molar mass of hydrogen according to the periodic table: 1 * 2 = 2.
2) Find the amount of substance hydrogen. To do this, divide the mass of hydrogen by its molar mass: 12/2 = 6 mol.
3) According to the reaction equation, there are two moles of water for one mole of hydrogen. This means that the amount of water substance is: 6/2 = 3 mol.
4) Find the molar mass of water: 1 * 2 + 16 = 18.
5) The mass of water is: 18 * 3 = 54g – the answer.